Apparatus for shielding pail open tops while spraying body exteriors



R m% mum aw Mmw A G v @m R B PM S F APPARATUS FOR SHIELDING PAIL OPEN TOPS INVENTOR Buz'rou LGPMBLE 9, I ATTORNEYS United States Patent 3,296,999 APPARATUS FUR SHEELDHNG PAlllL OPEN TGPS WHILE SiPRAYlNG BODY EXTERIURS Burton L. Gamble, Hinsdaie, IlL, assignor to Continental Can Company, Inc, New York, N.Y., a corporation of New York Filed Nov. 27, 1963, Ser. No. 326,428 5 Claims. (Cl. 1l8--2) This invention relates to spraying apparatus and more particularly to shielding apparatus for open tops of pails or other containers while spraying body exteriors.

A disadvantage arising from lacquer-spraying the eX- terior of a metal pail having an open top is that some of the spray is deposited on the inside surface of the pail in the marginal area adjacent the top which finally results in that area having an objectionably different or darker color. Heretofore, an attempt has been made to circumvent this disadvantage by placing a cover plate on the top of the pail before spraying operation and removing the cover thereafter. However, this procedure requires the employment of manual labor which is undesirable because it adds to the cost of making a pail.

It is an object of the present invention to automate the spraying procedure by eliminating the aforementioned manual placement of a coverplate.

.In accordance with the present invention, the pails or containers to be sprayed are placed on spaced pads carried by a conveyor. The pails are transported in single file past the spraying nozzles and means are provided for rotating the pads and pails. Before the pails enter the spraying zone, they pass beneath an endless stainless steel belt which is disposed above the open tops of the pails in spaced relation thereto. A stream of air from a manifold is directed beneath the stainless steel belt and between it and the open top of the pails during the spraying opera tion for deflecting any of the sprayed material that would otherwise enter the pail and be deposited on the top area of the interior surface of the pails. During the spraying operation, some of the sprayed material will be deposited on the stainless steel belt. Therefore, it is another object of this invention to provide means for washing, scrubbing and wiping the belt for removing the sprayed material therefrom.

Another object of this invention is to provide an apparatus for spraying a coating upon a container or other article, the apparatus comprising a conveyor means for transporting the article through a spraying zone, support means on the conveyor means for supporting the article, spraying means for directing a coating of material upon the article, masking means for shielding a portion of the article to prevent a coating from being applied thereto, means for reciprocating the spraying means along the spraying zone, and means for synchronizing the travel of the spraying means with the travel of the conveyor means.

Another object of this invention is to provide spraying apparatus, of the type set forth above, wherein the masking means includes an endless belt disposed adjacent to the article and means are provided for directing a sheet of air between the belt and the article toward the spraying means.

Another object of this invention is to provide the abovementioned spraying apparatus with means for cleaning the endless belt to remove coating material therefrom.

Another object of this invention is to provide the abovementioned spraying apparatus with means for operating the spraying means during one phase of reciprocation thereof, and detecting means for detecting the presence of an article upon the support means, the detecting means being operable to activate the spraying means when an article is detected on the support means.

Another object of this invention is to provide an appa- Patented Jan. 10, 1E6? ratus for spraying containers having open tops, the apparatus comprising an endless conveyor chain mounted for travel in a predetermined path, support pads carried by the conveyor chain, a plurality of spindles journaled on the conveyor for rotatably supporting the support pads, a sprocket aifixed to each of the spindles, means disposed in the path of travel for rotating the sprockets, the spindles and the support pads; a spray gun, mounting means for supporting the spray gun alongside the path of travel of the conveyor chain, drive means for reciprocating the spray gun on the mounting means, means for actuating the spray gun to spray a coating material onto the containers, detecting means for activating the spray gun when a container is detected on one of the support pads in alignment with the spray gun, an endless masking belt having a flight thereof spaced closely adjacent to the top of the containers passing in front of the spray gun, means for directing a sheet of air between the tops of the containers and the masking belt toward the spray gun, whereby coating material being sprayed upon the containers is prevented from entering the open tops thereof, drive means for rotating the masking belt, and means for cleaning the masking belt.

A further object of the present invention is to provide the above-described spraying apparatus with means for synchronizing the travel of the spray gun with the travel of the conveyor chain during a spraying operation.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a fragmentary perspective view of the spraying apparatus embodied in the present invention, and also schematically illustrates the control means for the spraying apparatus.

FIGURE 2 is a fragmentary vertical. sectional view, taken on line 22 of FIGURE 1, and illustrates a preferred manner of mounting the spray gun carriage and the rotatable support pad.

Referring to the drawing in detail, there is illustrated in FIGURE 1 a spraying apparatus, which is generally indicated by the numeral W, for spraying a lacquer or other coating material onto articles or containers such as the series of open top pails 11.

Each of the pails 11 is supported on a support pad 12 which is securely fastened to a spindle 13. Each of the spindles 13 is keyed, or otherwise suitably secured, to a sprocket 14 such that rotation of the sprocket 14 results in rotation of the support pad 12 and spindle 13. Each of the spindles 13 includes an enlarged shoulder portion 15 which supports the spindle 13 on an anti-friction roller bearing 16 which is carried by a housing 17. Each of the bearing housings 1'7 is securely fastened to a pair of links 13 which are part of a conveyor chain 19. The conveyor chain 19 is preferably endless and may be suitably driven by a sprocket 2t]! suitably affixed to a drive shaft 21.

A pair of spraying guns 25 is mounted for reciprocating movement alongside the path of travel of the pails Ill and conveyor chain 1?. The spraying guns 25 are preferably adjustably attached to an upstanding post 26 by suitable fastening clamps27. The upstanding post 26 is secured to a carriage 28 which is mounted for sliding movement on a stationary slide bar 29.

The spraying guns 25 and carriage 28 are suitably driven in a forward direction, to the left as illustrated in FIGURE 1, by a toothed cam 30 which is suitably affixed to a driven shaft 31 and engages a pin 32 that is fastened to the carriage 28. While the cam 30 is illustrated as having only one tooth, and only one pin 3.2 is provided on the carriage 28, it is apparent that more than one tooth may be provided on the cam 30 and more than one pin may be provided on the carriage 28.

The return stroke of the spraying guns 25 and carriage 28, i.e., to the right as illustrated in FIGURE 1, is provided by a suitable tension spring 33 which is suitably attached to the carriage 28 and to the slide bar 29. As the cam 30 drives the carriage 28 in the forward direction, the spring 33 is tensioned such that when the tooth of the cam 30 clears the pin 32 the spraying guns 25 and carriage 28 are rapidly moved to the right in preparation for a subsequent spraying operation.

It is preferable that some means be provided for synchronizing the movement of the conveyor chain 19 and the forward movement of the spraying guns 25. A suitable power transmission means is schematically illustrated by the broken line 34 as is shown in FIGURE 1. It is only necessary that this power transmission means suitably couple the driven shaft 31 to the drive shaft 21 and may be accomplished by a conventional gear train or chain and sprocket.

The spraying guns 25 may be operated by a suitable pump 35 which is driven by a drive shaft 36. A supply line 37 connects the pump 35 to a reservoir 38 which contains lacquer or other coating material 39. The coating material 39 is drawn through the supply line 37 and is forced by the pump 35 through a conventional solenoid valve 40 into delivery lines 41 which are connected to the spraying guns 25. A suitable check valve 42 is provided between the pump 35 and the solenoid valve 4-0 for returning coating material to the reservoir 38 during the time that the solenoid valve 40 is closed.

It is very desirable that the spraying guns 25 emit a spray of coating material only during the forward travel of the carriage 28 and only When a pail 11 is present in front of the spraying guns 25. A suitable control circuit for the solenoid valve 40 is shown as including a power source 43, a photoelectric cell 44 and a switch 45. The solenoid valve 4-0 is of a type which permits passage of a coating material from the pump 35 to the delivery lines 41 only when there is no current flow in the electrical circuit. During forward movement of the spraying guns 25 and carriage 28, i.e., to the left as is shown in FIGURE 1, the switch 45 is held open by a cam 46 that is mounted on the driven shaft 31. During the return stroke of the spraying guns 25 and carriage 28, the switch 45 is closed and current flows in the circuit causing the solenoid valve 46 to shut off flow to the delivery lines 41. During this time, the coating material is forced through the check valve 42 and is returned to the reservoir 38.

The photo-electric cell 44 may be mounted on a bracket 46' that is attached to the upstanding post 26. A source of light 47 is mounted in a housing 18 that is attached to the carriage 28 by a support arm 49. The light 47 emits a beam of light, as is indicated by the arrow 50, which beam of light is directed onto the photo-electric cell 44 carried by the bracket 46'.

As is shown in FIGURE 1, the light 47 is connected across the power source 43 so as to produce a constant beam of light. As long as the light 47 shines on the photo-electric cell 44, current flows to the solenoid valve 40 and the coating material is prevented from entering the delivery lines 41. It is apparent from the foregoing that the spraying guns 2.5 emit a spray of coating material only on the forward stroke of the carriage 28 and only when a pail 11 is present to break the light beam which shines o the photo-electric cell 44.

The pails 11 and the spindles 13 are rotated about their vertical axis by an endless drive belt or chain 55 which is driven by a drive sprocket 56. The chain 55 is held in engagement with the sprocket 14 by a conventional ten- ,sioning roller 57 such that each pail 11, pad 12 and spindle 13 is rotated during the time that the pail 11 is in alignment with the spraying gunsZfi. It is apparent, from the foregoing, that the exterior surface of each of the pails 11 is completely sprayed with coating material.

It is an important feature of this invention that a masking means, generally indicated by the numeral 60, is provided to prevent coating material from being sprayed on the inside surfaces of the pails 11 in the marginal areas adjacent the tops thereof. An endless stainless steel belt 61 is trained over a plurality of guide rollers 62. The belt 61 is driven by a drive roll 63 which has teeth 64 that fit into apertures 65 disposed along the longitudinal center line of the belt 61. Before the pails 11 enter the spraying zone adjacent to the spraying guns 25, the pails 11 pass beneath a horizontal flight 66, of the steel belt 61, which is disposed above the open tops of the pails 11 in spaced relationship thereto. A stream of air 67 is blown from a manifold 68 and is directed beneath the belt 61 and between it and the open tops of the pails 11 during the spraying operation for deflecting any of the sprayed coating material that would otherwise enter the pail and be deposited on the top therein of the interior surface thereof. A damper plate 69 is preferably supported by a pair of hanger straps 70 and is disposed above the horizontal flight 66 of the steel belt 61. The damper plate 69 minimizes any fluctuation of the horizontal flight 66 of the belt 61 and thereby prevents interference with the flow of the stream of air 67.

Some of the sprayed coating material will be deposited, as at 75, on the stainless steel belt 61. A cleaning means, generally indicated by the numeral 76, is provided for cleaning deposits of sprayed coating material from the belt 61. An upper flight 77 of the belt 61, is immersed in a suitable solvent 78 which is contained in a tank 79. A wash sleeve 89 is fixed to a driven roll 81 and is rotated to apply solvent 78 to the belt 61. A pair of scrubbing rollers 82 are disposed on opposite sides of the belt 61 and are rotatably driven to remove any deposits of coating material therefrom. After the belt 61 has been cleaned by the wash sleeve and the scrubbing rollers 82, the belt is wiped by a pair of squeegee members 83 to remove any excess solvent therefrom.

It is apparent from the foregoing that apparatus has been provided for spraying articles with coating material and that means have been provided for masking a portion of the articles so that coating material will be applied only where desired.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claimed subject matter.

I claim:

ll. An apparatus for spraying a coating material upon an article, said apparatus comprising a conveyor means for transporting said article through a spraying zone, sup port means on said conveyor means for supporting said article, spraying means for directing a coating of material upon said article, masking means for shielding a portion of said article to prevent a coating from being applied thereto, said masking means including an endless belt having a horizontal flight thereof disposed adjacent to and slightly spaced above said article, and means for directing a sheet of air between said belt and said article toward said spraying means.

2. The apparatus as defined in claim 1 wherein means are provided for cleaning said endless belt to remove coating material therefrom.

3. An apparatus for spraying a coating material upon an article, said apparatus comprising a conveyor means for transporting said article through a spraying zone, support means on said conveyor means for supporting said article, spraying means for directing a coating of material upon said article, masking means for shielding a portion of. said article to prevent a coating from being applied thereto, said masking means including an endless belt disposed above said article and presenting a horizontally disposed fiat fiight which is Wider than said article, means for directing a sheet of air between said horizontally disposed fiat flight and said article toward said spraying means, means for driving said endless belt, and means for cleaning said endless belt.

4. An apparatus for spraying containers having open tops, said apparatus comprising an endless conveyor chain mounted for travel in a predetermined path, support pads carried by said conveyor chain, a plurality of spindles journaled on said conveyor for rotatably supporting said support pads, a sprocket afiixed to each of said spindles, means disposed in the path of travel for rotating said sprockets, said spindles and said support pads; a spray gun, mounting means for supporting said spray gun alongside the path of travel of said conveyor chain, drive means for reciprocating said spray gun on said mountain means, means for actuating said spray gun to spray a coating material onto said containers, detecting means for activating said spray gun when a container is detected on one of said support pads in alignment with said spray gun, an endless masking belt having a flight thereof spaced closely adjacent to the top of containers passing in front of said spray gun, means for directing a sheet of air between the tops of said containers and said masking belt toward said spray gun whereby coating material being sprayed upon said containers is prevented from entering the open tops thereof, drive means for rotating said masking belt, and means for cleaning said masking belt.

5. Apparatus as defined in claim 4 including means for synchronizing the travel of said spray gun with the travel of said conveyor chain during a spraying operation.

References Cited by the Examiner UNITED STATES PATENTS 1,981,149 11/1934 Parker et al 1l8-301X 2,157,638 5/1939 Soubier 101-115 2,342,375 2/1944 Shurley 118-301 2,505,063 4/1950 Palermo 11830l 2,610,578 9/1952 Paasche 118301 X 2,690,731 10/1954 Gaiser 118-301 X 3,041,194 6/1962 Rosen et al 118301 X 3,086,495 4/1963 Knight 1l82 FOREIGN PATENTS 244,199 3/ 1912 Germany. 777,826 6/1957 Great Britain.

DANIEL BLUM, Primary Examiner. 

1. AN APPARATUS FOR SPRAYING A COATING MATERIAL UPON AN ARTICLE, SAID APPARATUS COMPRISING A CONVEYOR MEANS FOR TRANSPORTING SAID ARTICLE THROUGH A SPRAYING ZONE, SUPPORT MEANS ON SAID CONVEYOR MEANS FOR SUPPORTING SAID ARTICLE, SPRAYING MEANS FOR DIRECTING A COATING OF MATERIAL UPON SAID ARTICLE, MASKING MEANS FOR SHIELDING A PORTION OF SAID ARTICLE TO PREVENT A COATING FROM BEING APPLIED THERETO, SAID MASKING MEANS INCLUDING AN ENDLESS BELT HAVING A HORIZONTAL FLIGHT THEREOF DISPOSED ADJACENT TO AND SLIGHTLY SPACED ABOVE SAID ARTICLE, AND MEANS FOR DIRECTING 